Control of electric motors



June 8 1926.

R. HICGUET coN'rnoL oF ELECTRIC Moons Filed Maren s. 1924 5 Shee'cs--Sheei'l 1 In vemlor June 8 1926. f 1,587,645

R. HICGUET CONTROL OF, ELECTRIC MOTORS v Filed March 5. 1924 I' .'5 Sheets-Sheet 2 June 8 1926,

1,587,645 R. HICGUET CONTROL OF ELECTRIC MOTORS Filed March 5. 1924 3 Sheets-Sheet 5 Rohm Hlcgue* INVENTORI :Mh/L, il. Attorney.

Patented June 8, 19.26.

UNITED STATES 1,587,645 PATENT OFFICE.

ROBERT' HIGGUET, 0l' PARIS, FBANCEh ABSIGOR TO LA TRACTION ELECTRIQUE BATIONNELLE, 0F PABIS,`FRANCE.

coN'rnon or ELECTRIC morons.

Application med Iarch 3, 1924, Serial No.

The present invention has for its object a device adapted for the control of the electro-` magnetic change speed devices used in cooperation with electric motors and in particular with electric traction motors.

One feature ofthe invention resides in that the device comprises a dynamometer which is subjected to the act-ion or reaction of the resistance couple and is operatively connected to contact devices, relays, electromagnets and like known devices controlling the operation of the changespeed device, that is to say throwing on one or another speed, the change of speed being thus effectp ed according to the deformation of the elastic element of the dynamometer, the speed ofthe motor and the power torque being thus automatically varied in accordance with the resistance couple upon the drivenshaft.

This automatic control may be combined with a hand -controlled device adapted to reduce to a maximum the speed allowed by the dynamometer.

The dynamometer may also be used, as already known, for modifying the electric. constants of the motors vin case the latter are direct current motors so as to increase the variation of speed of the driven shaft and to render the change of speed progressive when the` elements in engagement in the electromagnetic change speed device, are changed under they/influence of the dynamometer.

In the appended drawings and by way of example:

Figs. 1 to 8 show diagrammatically difierent embodiments of the device according t0 the invention.

Fig. 9 shows diagrammatically a contact apparatus controlled by the dynamometer and adapted for use with a change speed device box with two operative positions.

Figs. 10 and 11 are diagrams ofhand operated devices for reducing the speed allowed by the automatic regulation, the device shown in Fig. 10 being a mechanical device, while Fig. 11 illustrates an electrical device.

-In the device shown in Fig. 1, 1 is the shaft of themotor 2- which rotatesftle driven shaft 3 through the medium of the electromagnetic change speed device of a known type 4, of the shaft 5 and of the elastic coupling 6 of a knownv construction. The

deformations of the elastic coupling 6 f1.0-

696,483, and in France November 19, 1923.

.the latter determinethe -displacements of the piece 7 which, through the medium of the contact apparatus, controls the change speed device.

' Fig. 2 shows a modification inwhich the reaction of the resistance couple takes place on one of the three elements of an epicycloidal gear set disposed between the electromagnetic change speed device'4 and the driven shaft 3. The shaft 5 of the box 4 carries a pinion 11 meshing with the planetary gears 12 and 13 connected to each other by a bridge piece 14 which is itself keyed to the shaft 3. The planetary gears engage on the other hand the outer toothed r' 15 t0 which is pivoted a rod 16 urged y a dynamometric spring 17 and actlng upon the arm 9 lof the contact apparatus 10 which controls the change speed device 4. According to the value of theresistance couple, and under the action of the spring 17, the ring 15 is displacedin either direction, and the rod 16 moves the arm 9 of the apparatus 10 which puts automatically in engagement the suitable pinion of the change 'speed device 4. p

In the modifications shown in Figs. 3, 4 and 5 the dynamometer is acted upon b the reaction of the resistance effort on the arings-of a gear transmission device.

Fig. 3 is a diagrammatic section and Fig. 4 a side view of a device, wherein the transmission of motion is eiected by means of gear wheels having parallel shafts. According to Figs. 3 and 4, to the shaft 5 of the change speed device 4 is keyed a pinion 18 drivingl a pinion 19 which is connected, by a Cardan joint 20 or by an elastic coupling, with the driven shaft 3.- The bearings 21 of the pinion 19 are 'movable with respect to the shaft carrying the plmon and are connected with a dynamometer 22. The

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deformations of the dynamometer 22 are transmitted by suitable levers 23 to the arm 9 of a contact apparatus 10 serving to control the change speed device according to the deformations of the dynamometer, and hence according to the variations of the resistance couple.

Fig. 5 shows a modification of the device illustrated in Figs. 3 and 4, and in ,which the shafts of the pinions 18 and 19, instead of being parallel, are at right angle, the pinions being in this case bevel gear wheels. Obviously, the angle between the axes of the pinions may be as desired, these gears having then a corresponding shape. lt is also obvious that the Cardan joint shown in Figs. 3 and 5 may be placed on either side of the gear set.

Fig. 6 shows diagrammatically a modification in which the resistance couple acts directly upon the Worm of a worm transmission gear, this device being already known in, itself. rll`he action of the resistance couple imparts to the worm a longitudinal translation which is transmitted to the arm of the contact box controlling the electro-magnetic change speed device. In Figure 6, 4 is the change speed device which controls the driven shaft 3 through the medium of a worm gear, the worm 24 Whereof engages the worm wheel 25 keyed to the shaft 3. The worm is operatively connected to the change speed device either by means of a slide shaft 26 or by means of a exible or elastic coupling, in such manner that the lengthwise reaction of the couple shall be supported by a dynamometer 27 connected to the worm 24 by the piece 28. The deformations of the dynamometer result in an angular displacement of the arm 29, which cooperates with a contact apparatus 10 controlling the operation of the 4change speed device 4.

lf required. the dynamometer may as well be placed before the change speed device. for instance asin Fig. 7. lin said figure the stator 30 of the motor 2 is pivotally mounted on a shaft'31 which coincides with the axis of the motor: this shaft 31 is supported by independent bearings 32. This stator is connected with ,a dynamometer 33 which controls, by means of suitable levers 34 and an arm 35, a contact apparatus 10 with two operative positions a and b. The contacts 36, 37 close, by means of the arm 35, distant control circuits operating the change speed device 4 which is actuated by the motor through a suitable mechanical transmission. For example if the arm 35 closes the circuit of the contact 37 corresponding to the maximum couple of the motor, this circuit will provide for the engagement of the pinions in the change speed device which correspond to the lower speed for the driven shaft. @n thecontrary, when the contact 36, corremenait sponding to the minimum couple, is closed by the arm 35, this will cause the engagement in the change speed device of the pinions giving the high speed to the driven shaft.

Fig. 8 shows diagrammatically and by way of example a device designed for use Y with direct current motors and in which the dynamometer, placed 'before the change speed device, is subjected' to the resistance couple through the medium of any of the.

above-described devices. In this arrange- `1nent, the deformations of the dynamometer action or reaction of the resistance couple is made to control the arm 9 of a contact apparatus 10. The latter is provided with two sets of contacts: One set 40, 41 is used for the control of the change-speed device, while thecontacts 39'of the other set are used for the control of the electric constants ofthe motor, by means of rheostats, relays or any like devices.

The operation of the whole device is as follows: If for example the minimum couple corresponds to the position of the arm 9 upon the contact 40, the connection of the contacts 39 are such that the speed of the motor will be a maximum when the arm 9 reaches the-position 40, and thatthe speed will be a minimum when this arm reaches the position 41. When the contact 40 is reached by the arm 9 (minimum couple), this' contact will cause the engagement in the change-speed device 4 of the elements giving the speed 1inst above. to the driven shaft 3, and when the contact 41 is reached by the arm 9 (maximum couple) this contact will cause the yengagement in the changespeed device of the elements giving the speed just below, to the driven shaft 3. In this manner, the speed of the driven shaft 3 will vary in a progressive manner by reason of the control effected upon the electric constants of the motor between the different positions of the gears in the change-speed device 4.

lt is obvious that the contacts controlled bythe dynamometcr 38 in thc above-mentioned device, can control several changespeed devices when several motors are used to drive the salue driven shaft. or when one .single motor is used to drive several driven shafts. The apparatus illustrated in Fig. 9 is a modification of the contact apparatus shown in Fig. 8, the dynamometer, notI shown, but operating the rods 42, vbeing lao placed between the change-speed device and the driven shaft. The rods 42 actuate the two movable contact pieces 43 and 44 which may take the various positions from a to z'. The contact 43, which constantly rubs upon the conductor 43, will control the operation of the changespeed device when touching the contact pieces 46 and 47; the contact piece 44 which makes contact with the conductor 44:L controls, through the contact pieces 45, the electric constants of the motor so as to vary the speed of the latter. If

thc contacts 43 and 44 are impelled for ex' ample according to the arrow F, the first speed of the change-speed device (the slowest) will remain in engagement until the Contact piece 43 touches the contact piece 46, that is to say, for the positions from a to e of the contact 44. In the motion in the contrary direction to the arrow F, the second speed will remain in engagement unt-il the contact piece 43 touches the contact piece 47, that is to say, in the positions from z' to d for the contact 44. The contact 44 will act upon the electric constants of the mo tor, so that when the contact 44 is at a the speed of the motor is a minimum, and when said contact is at i the 'speed is a maximum. This speed will 'be also a minimum at the moment of the change-over to the second speed, i. e., when the contacts are at e. F urther, the speed of the motor vwhen the contacts are at d, at the time of the return to the first speed, will be greater than when the4 contactsare at a, so that the speeds of the driven shaft will be very close together for the position d and the position e, and there will be uo shocks during the cha-nge from the second speed to the lirst in the change speed device and inversely.

` The automatic devlces according to the present invention, will be advantageouslyv used conjointly with a hand operated control device for reducing -the s eed of rotation of the motor permitted by t 1e automatic regulation.

In Fig. 10, a dynamometer, 48, responsive to the action or reaction of the resistance eiort, operatesthrough the medium of the levers or rods 49 and 50, the arm 9 of a contact box 10 controlling the operation of an electro-magnetic change speed device. The rods 49 and50. are connected together byl a. spring 51. The arrangement of the parts is such that when the arm 9 is at its end position a the speed decreases or has already reached a minimum and whenthis arm is at the end position b the speed increases or has )already reached a maximum. But if the spring 51 is stretched, by pulling on the rod 52, the arm 9 is brought towards the position a, and the speed tends to be reduced." Any movement of the rod 52 in the opposite direction might be performed until the rods 49 and 50 come int-o contact. In

this manner the variation of speed vby the hand operated rod` 52 can only take place between the minimum speed and the speed allowed by the automatic regulation. The spring 51 maybe used as a connection between any-two elements of the means operatively connecting the dynamometer to the movableV arm of the contact box.

In Fig.- 11, the contact box controls the operation of the electromagnetic changespeed device by the wires 53. 54, 55, 56, 57 whose number depends upon thc. number of speeds in the change-speed device. This control is effected by the combination of the contacts 58 and 59 with the contacts 60 and 6l. The contacts 58 and 59 are automatically actuated through the medium of the levers 62, by the dynamometer which is responsive to the action'of the resistance couple; the contacts 60 and 61 are actuated at will by a separate control 63. These contactsr may take the positions, a, b,c, d, e. The position a corresponds to the slowest speed and e corresponds to the highest speed. The current entering through the terminal 64 i's supplied to the contacts 53, 54, 55, 56, 57 through the connections established by the contacts 58, 59, 60 and 61.

The `operation of the whole device is as follows: The contact 60 can, according to its position, supply the current to the contact pieces 65, 66, 67, 68, 69 upon which the contact piece 58 may rub. The contact 58 can,

into the contact pieces 70, 7l, 72, 73, 74, 75,

76, 77, 78, 79. The c'ontact 58 is constituted of a set of small contacts 58n insulated from each other, so as to provide for the passa e of the current in the vertical direction of t gure and to break the same in the horizontal sense. The contacts 59 or 61 then lead the current from the preceding cont-acts to the contacts 53, 54, 55,56 or 57. f

Fig. 11 shows that the cont-acts 58 and 59 being in the position c and the contacts 60 and 61 in the position d. the current will enter the terminal 55 (position c) in spite of the fact that the contacts 60 and 61, actuated at will by the arm 63, are in the position d. If the contacts 60 and 61 are moved towards theA position'b, the current will reach the termlnal 54 through the contact ieces 60, 66, 58, 71, 61, 54.. The circuit ending at the terminal 55 is in fact broken between the contact 60 and the contact piece 67. It is readily observed that one can reduce the speed allowed by the automatic control, by

Obviously, many constructional modiica- I tions may be brought to the devices above described without departing from the scope v di' of the invention. ln particular, the described contact elements can be replaced by relays, electro-magnets or like. devices allowing the control of the electro-magnetic e change-speed device.

Having now described my invention, what l claim as new and desire to secure by Letters Patent is: L

1. A power plant comprising electric inotors, an electro-magnetic change speed device, a shaft 'driven by said motors through the intermediary of said changer speed device, electric means for controlling' said change speed device, a dynainon'ietcr subjected to the action of the resisting couple,

and means for operatively connecting said dynamometer to said control means for the change .speed device.

2. A power plant comprising direct current electric motors, an electro-magnetic change speed device, a shaft driven by said motors through the 'intermediary of said change speed device, electric means for controlling said change speed device, means for cont-rolling the constants of said motors, a dynamometer subjected to the action of the resisting couple, and means for operatively and separately connecting said dynaniometer to sail control means for the change speed device and to said control inean's'for the constants of the motors. f

3. A. power plant vcomprising direct current electric motors, an electro-magnetic change speed device, a shaft driven by said motors through the intermediary of said change speed device, electric means for controlling said change speed device,y means for controlling the constants of said motors,'two sets of fixed contact piecesl respectively con- 40 nected with said control means for the change speed device and forthe constants of the motors, two movable cont-act pieces respectively cooperating with said sets of fixed contact pieces, a dynamometer subjected t0 the action of the resisting couple and means for operatively connecting said dynamometer to both movable contact pieces.

4. A power pla-nt comprising direct cur- I,rent electric motors, an electrofmagnetic change speed device, a shaft driven by said motors through the intermediary of said change speed device electric means for con trolling sai change speed device, means for controlling the constants of said motors, two sets of fixed contact pieces respectively con# nected with said control means for. the change speed device and for the constants. of the' motors, two movable contact pieces respectively cooperating with said sets of fixed 60 'contact pieces, a dynamometer subjected to the action ofthe resisting couple and means for operatively connecting said dynamometer to both movable contact ieces, the connec tions between the means or controlling the 5 constants of the motors and. the respective sets comprising one feed leemte set of fixed Contact pieces being such that the speed of the motion is a minimum when passing to a higher speed of the driven shaft and is a maximum when passing to a lower speed of the driven shaft.

5. A. power plant comprising electric inotors, an elect-ro-magnetic change speeddevice, a 'shaftfdriven by said motors through `the intermediary of said change speed device,

electric means for controlling said change speed device, a dynaniometer sub- ]ected to the action of the resisting couple,

and means including a yielding member for operatively connecting said dynamoineter to said control means for the change speed device and whereby relative movements of said control means are allorded with respect to said dynamo'meter for causing a reduction of lspeed of the driven shaft.

6. A power plant comprising electric motors, an electro-magnetic change speed device, a shaft driven by said motors through the intermediary of said change speed device, electric means for controlling said change speed device, a dynainometer subjected to the action of the resisting couple,

eleztric means embodying a set of successivev contacts for operatively connecting said dynainometer to said control means for the change speed. device, and a hand operated contact member adapted to short circuit the contacts established by the dynamometer and to substitute for the same contacts of the saine set corresponding to lower speeds for the driven shaft.

'i'. A power plant comprising electric mo.- tors, an electro-magnetic change-speed device, a shaft driven by said motors through theV intermediary of said change speed device, electric means for controlling said change speed device, a dynainometer subjected to the action ofthe resisting couple, electric means embodying three sets of fixed contacts for operatively connecting said dynamoineter to said' control means, said three set and ltwo outlet sets, a series of movable contact pieces actuated by said dynamometer for closing at the same time the contacts of the feed set which correspond to the running speed and to the lower speeds, a further movable contact piece also actuated by the dynamometer and adapted to connect said contacts of the feed set to that of the first outlet set which'corresponds to the running speed and a han operated contact member adapted to close any desired contact o f the second outlet 4set while 'opening atthe same time all the contacts of the feed setcorresponding to a speed higher than that corresponding' to the position of said handopeiated member.

In testimony whereof I have signed my name to this specification.

no'nirar meetinr- 

